The origin of the phrase is from the Half-Life 2 comic Concerned, based off of Pwned or Owned. It is Gordon Frohman's custom spray, which depicts his face with the words "You got Frohwned!!!" in orange. He didn't actually kill anyone. Instead (during one of his Counter-Strike: Source crossovers) he pushed one of his teammates, Geoff, out into the open to give the Counter-Terrorist team "suppressing fire" and decided it counted as his kill when Geoff died of snipers. This makes sense because Frohman is an idiot.